Sewing machine cutter



March 29, FOWLER SEWING MACHINE CUT TER Filed Aug. 11, 1964 00a for E. Few/s! I N VISA-717R Gad WW 1966 n. E. FOWLER SEWING MACHINE CUTTER March 29.

3 Sheets-3hecet .4

Filed Aug. 11, 1964 Fig. 8

March 29, 1966 E" FOWLER SEWING MACHINE CUTTER 5 Sheets-Sheet 3 Filed Aug. 11, 1964 Doctor E. Fowler INVENTOR.

1 BY (um Fun; 3M

United States Patent 3,242,392 SEWING MACHINE CUTTER Doctor E. Fowler, Rte. 1, Chicanlauga, Ga. Filed Aug. 11, 1964, Ser. No. 388,902 11 Claims. (Cl. 112-252) This invention comprises a novel and useful sewing machine cutter and more particularly pertains to a thread cutter attachment adapted to be mounted upon conventional sewing machines and to be operated by and simultaneously with the operation of the sewing machine to cut the chain or thread resulting from the normal sev ing operation. In certain types of industrial sewing machines and of the high speed type operating at from 2,000 to 5,000 r.p.m., it is customary-to provide mechanical cutting means to sever the chain or thread resulting from the operation of the sewing needle and to remove the severed thread by a vacuum suction line. However, considerable difficulty has been encountered in this op eration. Unless the thread is severed in relatively short lengths, it tends to clog the suction line which removes a severed thread thus interfering with the operation of the machine. When the thread cutting mechanism is of a bulky or cumbersome nature, its mass tends to inter fere with the normal operation of the machine or reduce its speed of operation producing an undesirable economic condition.

It is therefore the primary purpose of this invention to overcome the foregoing difficulty and provide a thread cutting attachment which when applied to a conventional high speed industrial sewing machine will be of extremely light weight, will operate simultaneously with and in accordance,with the state of operation of the machine and will sever the chain or thread resulting from the operation of the machine into various small pieces thereby insuring against the possibility of clogging against the vacuum thread removing line.

A further purpose of the invention is to provide an attachment in accordance with the foregoing objects which shall be of the minimum size and of the maximum compactness to enable it to be readily applied in very close quarters on various types of commercially available sewing machines. .7

Still another object of the invention is to provide a cutting attachment for sewing machines of the character above set forth which shall consist of a springurged floating knife or trimmer blade cooperating with the .power-driven knife which is operatively connected with and driven by some part of the sewing machine as, for example, by the feed dog thereof.

A still further purpose of the invention is to provide I a, thread cuttingattachment in accordance with the pre ceding objects which may be easily applied or removed, can be readily installed for service, shall offer minimum resistance to the normal passage of the threads from th sewing needles and shall be capable of being operated at very high speeds by severing the thread into very small pieces relative to the speed of operation of the sewing machine.

.These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIGURE 1 is a perspective view of a portion of a conventional type of high speed industrial sewing machine to which the cutter attachment of this invention has been applied, parts being broken away;

FIGURE} is a perspective view of the cutter attachment removed from the machine;

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FIGURE 3 is an end elevational view from the trimmer blade end of the attachment;

FIGURE 4 is an enlarged elevational view of a portion of the machine of FIGURE 1 showing the association of the attachment of this invention with the feed dog and sewing instrumentalities of the machine;

FIGURE 5 is a detail view in horizontal section taken substantially upon the plane indicated by the section line 5-5 of FIGURE 4 and showing further details of the interior of the cutter attachment of this invention;

FIGURE 6 is a further detail view in horizontal section taken substantially upon the plane indicated by the section line 6-6 of FIGURE 5 and showing in dotted lines the path of movement of the thread which is to be cut by the attachment;

FIGURES 7 and 8 are detail views in vertical transverse section taken substantially upon the planes indicated by the section lines 77 and 8-8, respectively, of FIGURE 6;

FIGURE 9 is a perspective view of the feed dog of the sewing machine to which the power operated cutter blade of this attachment is operatively connected;

FIGURE 10 is an exploded perspective'view of the components of this attachment;

FIGURE 11 is a top plan view of the attachment; and

FIGURE 12 is an end elevational view from the left side of FIGURE 11.

Reference is made first to FIGURE 1 which shows a fragmentary portion of a conventional sewing machine indicated generally by the numeral 10 and to which the thread cutting and removing attachment of this invention, indicated generally by the numeral 12 has been applied.

' The sewing machine may be of any conventional type, that ly applied to various other suitable types of sewing ma-' chines.

Inasmuch as the sewing machine itself is of conventional design, and is well understood by those skilled in the art, it is unnecessary to consider in detail its structure and functioning other than to note that the machine includes a reciprocating needle bar 14 carrying a needle 16, see also FIGURE 4, togetherwith a bed 18 and further having the conventional feed dog 20 disposed beneath the needle plate 22, :see also FIGURES 46 and 9. The machine further includes operating mechanism for driving the needle bar and feed dog in properly timed relation and whose construction and operation form in themselves no part of the invention claimed herein.

The thread cutting and removing attachment 12 consists of an elongated housing 30 which as shown in FIG- URE 2 is generally rectangular in cross-section, and which is removably mounted upon the sewing machine bed 18 at a convenient position thereon as set forth hereinafter. The housing is very compact so as to enable it to fit into the minimum space available upon the sewing machine bed. The housing 30 preferably comprises two body or housing sections 32 and 34 which are of the same uniform rectangular cross-sectional configuration and which provides an air passage extending therethrough from end to end thereof. The outer end of the housing section 32 is provided with a tubular boss or nipple 36 upon which is engaged a suction conduit 38 communicated with any suitable source of suction which thus in-- duces an airflow through the passage within the housing. As shown in FIGURES 5 and 6, the housing section 32 has an axial bore or passage 40 therethrough whose rearward end constitutes an outlet to which the suction conduit is connected. At its forward end, the passage 40 extends through a diametrically reduced axial tubular extension 42 which is detachably embraced by the rearward end of the housing section 34, which is removably secured and clamped upon the extension 42 as by fastening means 44. The other or forward end of the housing section 34 constitutes the open inlet of the air passage -through the housing and is in continuous communication with the passage 40 previously mentioned.

The attachment is mounted by any suitable means in adjustable pQsit-ion upon the bed of the sewing machine in such a manner that inlet of the air passage of the housing is disposed proximate and in close adjacent relation to the needle bar and needle and the feed dog of the sewing machine in order that the airflow within the passage may draw in and convey the end of a sewing stitch chain from the needle 16 and cause it to be severed and com-minuted into relatively small particles and to be removed and discharged from the sewing machine by the suction conduit 38.

Referring now to FIGURES 5, 6 and '10 it will be observed that the housing body extension 42 is provided with a further axially extending diametrically reduced projection 46 which constitutes a guide -for a trimmer blade "which is slidably received thereon. This trimmer blade indicated generally by the numeral 48 includes a cylindrical sleeve portion 50 which slidably embraces the projection 46 together with an axially extending crescentsha'ped finger 52 having a beveled cutting edge 54 at its extremity. The exterior surface of the projection 46 is cut away to provide a flat guide surface 56 while the finger 52 has a corresponding flat surface slidingly engaged thereon. Thus, rotation of the trimmer blade 48 is revented during its axial reciprocation upon the projecti-on 46. l

A compression spring -8 encircles the projection 46 and abuts against the extension 42 and the end of the sleeve 50 of the trimmer blade. This spring yieldingly urges the trimmer blade axially outwardly of the projection 46 and toward the inlet of the housing.

A trimmer blade guide sleeve 60 is disposed in the inlet end of the passage through the housing section 34 and as shown in FIGURE is C-shaped in cross-section and is adapted .to encircle projection 46 with the slot 62 of the guide sleeve registering with the flat portion 56 and slidably receiving the finger 52 therethrough. A fastening means 64 threaded through the housing section 34 engages the guide sleeve 60 and retains it in place, the sleeve itself, abutting against the end of the cylindrical portion 50 of the trimmer blade preventing withdrawal or the trimmer blade from the housing section under the thrust of the spring 58.

will be evident that by loosening the fastening means 68 and adiustably shifting the sleeve 60 axially in the bore in the housing section 34, the range of movement permissible for the trimmer blade 48 under the thrust of the spring 58 can be regulated, thereby controlling the length of the particles which are severed from the sewing stitch chain by the device.

As will be noted particularly from FIGURES 6, 10 and 2, the top wall of the housing or section 3.4 at the inlet of the housing is provided with a thread inlet notch 79 which is adjacent to the cutting edge 54 of the trimmer blade finger 52.

The trimmer blade thus constitutes a stationarily mounted but floating and axially reciprocating member. Cooperating with the trimmer blade is a cutter blade '72 having a cutting edge 74 and having a bracket portion 76 which by means of fastening screws 78 is detachab-ly secured to the side of the feed belt'20.

The arrangement is such that during the normal ope-r- :ation of the feed belt'by the machine, corresponding movement will be imported to the cutter blade '72 mounted thereon and the cutter blade cut-ting edge will enter the inlet of the housing section 34 and cooperate with the cutting edge .54 of the trimmer blade to thereby sever the end of the sewing stitch chain 80 as the latter passes over the trimmer blade cutting edge and into the air passage of the device.

Inasmuch as the reciprocating cutter blade 72. moves at the same rate of speed as the feed belt, it is evident that regardless of the speed of operation of the sewing machine, the chain 80 will be severed into pieces of the same size and thus will prevent the possibility of larger pieces clogging up the air passage or the suction conduit.

Owing to the resilent floating action of the trimmer blade, it will be evident that there is obtained an efiicient shearing action between the cutter blade and the trimmer blade, inasmuch as the latter will yield slightly at each contact of the cutter blade.

It will be observed that the trimmer blade is very lightweight in construction, being journaled and guided upon the projection 46 and subjected only to an axial end thrust at its cutting edge by virtue of the contact with the cutter blade 72. Thus, a relatively long period of useful service may be expected for the trimmer blade. Moreover, the latter can be readily replaced by simply removing the fastener 64 and the sleeve whereupon the trimmer blade may be withdrawn from the housing section 71 from the inlet end thereof.

The fastener 44- permits ready removability of the section 34 from the section 32 and also enables a slight relative rotational adjustment of these parts if necessary.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. In combination with a sewing machine having a bed, a needle bar carrying a needle, a feed dog and operating mechanism associated therewith, a sewing stitch chain cutting attachment comprising a housing adapted for mounting upon said bed, said housing having an air passage th-erethrough with an outlet remote from and an inlet proximate said needle bar and feed dog and disposed for receiving and conveying therethrough by airflow a sewing stitch chain, said outlet being connected to a source of suction, a trimmer blade mounted in said housing and having a cutting edge adjacent said passage inlet and across which a sewing stitch chain passes, a cutter bladev carried by and movable with said feed dog and having a cutting edge cooperating with said trimmer blade cutting edge for severing said sewing stitch chain, meanssmounting said trimmer blade in said housing for permitting axial movement and preventing rotationalmovement of said trimmer blade in said housing.

2. The combination of claim 1 wherein said trimmer blade cutting edge and said cutter blade cutting edgeare suction, a trimmer blade mounted insaid housing and having a cutting edge adjacent said passage inlet and across which a sewing stitch chain passes, a cutter blade carried by and movable with said feed dog and having a cutting edge cooperating with said trimmer blade cutting edge for severing said sewing stitch chain, a tubular guide in said housing, said trimmer blade having a'cylindrical portion journaled upon and slidably embracing; said guide,

spring means yieldingly biasing said trimmer blade toward said cutter blade.

4. The combination of claim 3 including an adjustable stop within said housing engageable with said trimmer blade and adjustably limiting its sliding movement toward said cutter blade.

5. In combination with a sewing machine having a bed, a needle bar carrying a needle, a feed dog and operating mechanism associated therewith, a sewing stitch chain cutting attachment comprising a housing adapted for mounting upon said bed, said housing having an air passage therethrough with an outlet remote from and'an inlet proximate said needle bar and feed dog and disposed for receiving and conveying therethrough by airflow a sewing stitch chain, said outlet being connected to a source of suction, a trimmer blade mounted in said housing and having a cutting edge adjacent said passage inlet and across which a sewing stitch chain passes, a cutter blade carried by and movable with said feed dog and having a cutting edge cooperating with said trimmer blade cutting edge for severing said sewing stitch chain, said housing including a pair of axially aligned housing sections comprising inlet and outlet sections, said outlet section having a diametrically reduced axial extension positioned within said inlet section, said trimmer blade including a sleeve slidably embracing and journaled upon said extension, means yieldingly urging said trunnion blade toward said cutter blade, said trimmer blade being confined within said inlet section.

6. The combination of claim 5 wherein said extension has a terminal portion with a fiat surface thereon, said trimmer blade including a finger extending from said sleeve and slidingly engaged on said flat surface.

7. The combination of claim 6 wherein said inlet section at the inlet of said passage has a notch positioned to receive a sewing stitch chain and guide across said trimmer blade cutting edge.

8. In combination with a sewing machine having a bed, a needle bar carrying a needle, a feed dog and operating mechanism associated therewith, a sewing stitch chain cutting attachment comprising a housing adapted for mounting upon said bed, said housing having an air passage therethrough with an outlet remote from and an inlet proximate said needle bar and feed dog and dis posed for receiving and conveying therethrough by airflow a sewing stitch chain, said outlet being connected to a source of suction, a trimmer blade mounted in said housing and having a cutting edge adjacent said passage inlet and across which said sewing stitch chain passes, a cutter blade carried by and movable with said feed dog and having a cutting edge cooperating with said trimmer blade cutting edge for severing said sewing stitch chain, guide means in said housing, and said trimmer blade having a portion thereof slidably mounted on said guide means.

9. The combination of claim 8 including spring means for yieldingly biasing said trimmer blade toward said cutter blade.

10. A sewing machine comprising a reciprocating needle, a feed dog reciprocating across the path of said needle, a sewing stitch chain cutting assembly, said assembly including a first blade carried by and movable with said feed dog, and a second blade mounted substantially in line with the path of travel of said first blade, and means mounting said second blade for permitting axial movement of said second blade in response to contact by said first blade whereby cutting action between said first and second blades will be efiected.

11. The combination of claim It) wherein said mounting means comprises guide means, said second blade including a portion slidably mounted on said guide means, and spring means between said guide means and said portion for yieldingly biasing said second blade toward said first blade.

References Cited by the Examiner UNITED STATES PATENTS 3,058,438 10/1962 Russell 112252 3,139,849 7/1964 Cohen 112252 3,143,987 8/1964 Daniel 112252 3,149,594 9/1964 Buckreus 112252 FRANK J. COHEN, Primary Examiner.

JORDAN FRANKLIN, Examiner.

M. I. COLITZ, J. R. BOLER, Assistant Examiners. 

1. IN COMBINATION WITH A SEWING MACHINE HAVING A BED, A NEEDLE BAR CARRYING A NEEDLE, A FEED DOG AND OPERATING MECHANISM ASSOCIATED THEREWITH, A SEWING STITCH CHAIN CUTTING ATTACHMENT COMPRISING A HOUSING ADAPTED FOR MOUNTING UPON SAID BED, SAID HOUSING HAVING AN AIR PASSAGE THERETRHOGUH WITH AN OUTLET REMOTE FROM AND AN INLET PROXIMATE SAID NEEDLE BAR AND FEED DOG AND DISPOSED FOR RECEIVING AND CONVEYING THERETHROUGH BY AIRFLOW SEWING STITCH CHAIN, SAID OUTLET BEING CONNECTED TO A SOURCE OF SUCTION, A TRIMMER BLADE MOUNTED IN SAID HOUSING AND HAVING A CUTTING EDGE ADJACENT SAID PASSAGE INLET AND ACROSS WHICH A SEWING STITCH CHAIN PASSAGE INLET AND CARRIED BY AND MOVABLE WITH SAID FEED DOG AND HAVING A CUTTING EDGE COOPERATING WITH SAID TRIMMER BLADE CUTTING EDGE FOR SEVERING SAID SEWING STITCH CHAIN, MEANS MOUNTING SAID TRIMMER BLADE IN SAID HOUSING FOR PERMITTING AXIAL MOVEMENT AND PREVENTING ROTATIONAL MOVEMENT OF SAID TRIMMER BLADE IN SAID HOUSING. 